#!/bin/bash

# This sctipt can be added in /etc/inittab in any system with traditional init systems
# to replace the login prompt whith a selection of VMs

# This script uses virsh to get list of all local lxc and qemu VMs managed using libvirt.
# The list will be displayed using dialog. When selecting a VM, this script attempts to
# get a spice or vnc display. It will connect to those with spice-client or directvnc.
# If no display is available, virsh console is used to connect to the vm console.

login_target_list="";
login_target_list_count=0

function quote {
  local quoted=${1//\'/\'\\\'\'};
  printf " '%s'" "$quoted"
}

function getTitle {
  case "$1" in
     lxc) virsh -c lxc:/// desc --title "$2";;
    qemu) virsh -c qemu:///system desc --title "$2";;
  esac
}

function addLoginTarget {
  i=$login_target_list_count
  login_target_list="$login_target_list""$(
    printf "%s" "$2" | grep -v ^$ |
    while IFS= read -r name || [[ -n "$name" ]]
    do
      i="$(expr $i + 1)"
      echo -n '"'
      echo -n "$i"
      quote "$1"
      quote "$name"
      echo '"'
    done
  )
"
  login_target_list_count="$(printf "%s" "$login_target_list"|wc -l)"
}

function chooseTarget {
  entries=$(for entry in "${login_list[@]}"; do {
    eval "e=($entry)"
    title="$(getTitle "${e[1]}" "${e[2]}")"
    echo -n "${e[0]}"
    quote "$(printf "%-6s %-10s %s" "${e[1]}" "${e[2]}" "$title")"
    echo -n " "
  } done)
  target_index=$(eval "\
    dialog --stdout --cancel-label "Aktualisieren"\
      --menu \"Umgebung waehlen (\$(basename \"\$(tty)\"))\" 0 0 \
      $login_target_list_count $entries
  ")
  if [ -z "$target_index" ]
  then target=(-1 exit none)
  else eval "target=(${login_list[$(expr $target_index - 1)]})"
  fi
  clear
}

function buildTargetList {

  addLoginTarget login "$(hostname)"
  addLoginTarget lxc   "$(virsh -c lxc:///        list --all --name)"
  addLoginTarget qemu  "$(virsh -c qemu:///system list --all --name)"

  eval "login_list=($login_target_list)"
}

function use_exit {
  true
}

function use_login {
  login
}

function virsh_show_display {
  uri="$(virsh domdisplay --type spice "$domain" 2>/dev/null)"
  if [ $? == 0 ]
  then
    printf "%s" "$uri" | grep -o '[^/]*$' | tr ':' '\n' | {
      read domain
      read port
      export domain
      export port
      CMD_LINE='spicec -f -h "$domain" -p "$port"' xinit /usr/local/bin/meval
      unset domain
      unset port
    }
    return 0
  fi
  uri="$(virsh domdisplay --type vnc "$domain" 2>/dev/null)"
  if [ $? == 0 ]
  then
    directvnc "$(printf "%s" "$uri"|grep -o '[^/]*$')" -m '' -e rre -b 24
    return 0
  fi
  virsh console "$domain"
  return $?
}

function use_libvirt {
  domain=$1
  clear
  virsh start "$domain" 2>/dev/null
  virsh_show_display
}

function use_lxc {
  LIBVIRT_DEFAULT_URI=lxc:/// use_libvirt "$@"
}

function use_qemu {
  LIBVIRT_DEFAULT_URI=qemu:///system use_libvirt "$@"
}

buildTargetList
chooseTarget

type=${target[1]}
name=${target[2]}

"use_$type" "$name"